replicaAvailabilityZones - A list of Availability Zones to be used for the read replicas.
The number of Availability Zones in this list must match the value of ReplicaCount or ReplicasPerNodeGroup if not specified.
slots - A string of comma-separated values where the first set of values are the slot numbers (zero based), and the second set of values are the keyspaces for each slot.
The following example specifies three slots (numbered 0, 1, and 2): 0,1,2,0-4999,5000-9999,10000-16,383 .
If you don't specify a value, ElastiCache allocates keys equally among each slot.
When you use an UseOnlineResharding update policy to update the number of node groups without interruption, ElastiCache evenly distributes the keyspaces between the specified number of slots. This cannot be updated later. Therefore, after updating the number of node groups in this way, you should remove the value specified for the Slots property of each NodeGroupConfiguration from the stack template, as it no longer reflects the actual values in each node group. For more information, see UseOnlineResharding Policy .